Abstract
Steganographic systems attempt to hide communication by embedding messages in an innocuous looking cover medium. Current steganographic systems provide relatively secured hidden data with small capacity for steganographic messages. In this paper, a new technique is introduced to hide data in the least significant bits (LSB) of the discrete cosine transform (DCT) coefficients of JPEG images. This technique embeds data in a way that maximizes the ratio between even and odd DCT coefficients so as to preserve the first order statistics of JPEG images. Message bits are divided into segments and each segment is possibly modified by embedding the bitwise complement so as to ensure a high ratio between even and odd coefficients. The embedding process is referred to as the hiding appropriate messages (HAM) algorithm. The HAM algorithm searches for optimum segment length to offer high capacity, approximately 0.36 bits/pixel, with statistically minimal changes compared to existing steganographic algorithms. A comparison between HAM and existing steganographic systems is presented. [PUBLICATION ABSTRACT]